When it comes to pruning, it is of course not enough to simply grab a pair of scissors and start cutting. But not only the how, but also the when is relevant - a pruning at the wrong time leads to an unwanted reaction or to a high risk of illness.

In the past, trees were usually cut in late autumn or early spring - when they were dormant. Today, however, tree care experts recommend doing pruning work during the growing season between March and September.

Why? Summer pruning is more gentle, wound healing begins immediately, and there is no risk of frost damage to the wound site. Nevertheless, the cut in the hibernation has some few Advantages over cutting during the growing season.

Winter Pruning: Tree pruning in late fall/winter/spring

Since time immemorial, deciduous trees and other deciduous trees and shrubs have been pruned in early spring or late winter. A cut in suitable weather in January or February - i.e. well before budding - also has advantages:

  • No leaves are removed and therefore fewer nutrients, which weakens the tree less.
  • due to the lack of foliage, it is easier to see where to cut
  • Winter pruning stimulates increased sprouting in spring, since the reserve substances in all leaves have already been stored and after pruning more energy is stored in the roots for fewer buds.
  • Disadvantage: At temperatures <0°C after the cut, the frost can penetrate into the now open area and the branch or tree can be damaged.

So, winter pruning brings one thing above all - wood growth. If I cut my young fruit trees, which should still grow vigorously, this must of course be done in late autumn or in February at the latest. If I cut my 15-year-old maple, which is already getting too big for me, then I should definitely do it in the summer to remove leaves and not stimulate growth any further.

Summer pruning: Tree pruning in summer/autumn

In the meantime, there is a tendency in tree care to cut during the growing season. The tissues are already active and the "healing" (sealing off and flushing) of the wounds begins immediately. In addition, the cut trees react less strongly with new shoots, "water shoots", which are worthless for the crown structure, occur much more rarely. Advantages of the summer cut:

  • The tree is still in the middle of growth and can therefore close wounds more quickly.
  • Many fungal pathogens are mainly active in late winter / spring, which is why infection is more likely then.
  • You have a better view of which branches are taking away too much light and therefore need to be removed.
  • The early pruning provides the tree with plenty of light and air before the winter break.
  • There are no possible frosts that would further weaken the freshly cut tree.
  • The growth is not additionally stimulated because the leaf mass is removed - reactions to the cut (water shoots, unintentionally strong and numerous sprouting) are less strong and chaotic.
  • The growth is slowed down the most if you cut directly at the sprouting - but this also weakens the tree the most.

The summer cut extends from March to the end of September. In principle, you can always cut during this period, but there are certain unfavorable situations:

  • Midsummer: In July, when it is particularly hot, it is not advisable to cut too hard. Parts of the crown (bark) that are normally in the shade are suddenly exposed to direct midsummer sun. “Sunburn” can occur, damaging the cambium and cracking the bark. This applies above all to tree species with dark bark (e.g. cherry) or with very thin bark (e.g. common beech).
  • Strong wind: If the trees are exposed to strong wind and weather events and parts of the crown are suddenly exposed to this wind and weather, for example due to the removal of individual long branches, it can happen that they break more easily due to the exemption.
  • Old, slow-growing tree species: Here you want to encourage budding, so winter pruning is also justifiable.

Basically… .

Tree pruning is possible all year round, but you should know what you want to achieve. If you cut a tree in winter that you don't really want to get any bigger, you can simply cut it again in summer. If you want to make major corrections to fruit trees, you should definitely do this in summer, even if the tree is still supposed to grow. Here the cut is also divided between summer and winter.

Background: How does the tree react to the cut?

Trees don't heal their wounds - they bulkhead. When cut, the tree reacts in the same way as when a branch breaks. At the break or cutting point, the tissue inside is sealed off in such a way that neither air nor pathogens can penetrate deeper into the wood. The wood tissue that is separated from the healthy tissue by the partition dies off. In addition, the wound is closed again from the outside by overflowing. The wood tissue that is separated from the healthy tissue by the partition dies off. The right incision now decides whether this process can run quickly and cleanly. In addition, under the trees there are bad and good “detachments”. If the tree does not manage to seal off and overflow successfully, the slow decay begins from the inside, since decomposing microorganisms can spread in the tree and penetrate deeper and deeper into it.

Research on the subject has shown that trees are most efficient at performing this process during the growing season between March and September. If you cut during the hibernation, larger areas of dead wood tissue are created. If you cut branches with a diameter that is too large (>10cm or >5cm in the case of poor "sealing off"), the tree will not be able to build up the safe barrier between healthy and dead wood tissue.

In cooperation with

Category:

Trees